System for printing three dimensional objects using a liquid-matrix support

ABSTRACT

A system for printing three dimensional objects using a liquid-matrix support includes a motor, a resin, a stage, oil, and a light projecting source. The motor is an operating interface that is adapted to move the stage in an upward or in a downward direction. The resin in the system comprises a light polymerizable liquid. The light from the light projecting source is projected onto the resin to provide a shape to the three dimensional objects. The stage is adapted to move in the upward or in the downward direction to support the growing layers of the printed three dimensional objects. The oil is a non-aqueous hydrophobic and oleo-phobic component that is coupled at an interface with the resin by a liquid-matrix support which includes an additive. The light projecting irradiates the resin, and, in a preferred embodiment, irradiation passes through the oil to the resin. The liquid-matrix support enhances speed, resolution and provides smooth finishing texture to the printed three dimensional objects of large and small dimensions.

BACKGROUND Technical Field

The embodiments herein generally relate to printing of three dimensionalobjects using a liquid-matrix support, and, more particularly, a systemfor printing the three dimensional objects using the liquid-matrixsupport.

Description of the Related Art

Step-wise or layer-by-layer or sequential three-dimensional objectbuilding was the first technique adopted for three-dimensionalmanufacturing techniques. The three-dimensional manufacturing techniquesare largely referred as three dimensional printing or additivemanufacturing. Additionally, the above-mentioned techniques are based onthe solidification of a liquid resin that is referred to as a photocurable technique. The photo curable technique comprises an initiatormaterial that is mainly UV or near-UV active that generatesfree-radicals that initiates the polymerization of the resin resultingin networking among the resin molecules.

Solidification of the liquid resin is also referred as curing, whichoccurs throughout a top-to-bottom or a bottom-to-top printing dependingon the technology used. The liquid resin polymerizes in such a way toobtain an additional layer to be built on the surface of the growingobject by a light irradiation sequence.

In top-to-bottom printing, layers of the cured resin are formed at thetop surface of the growing object, followed by a lowering of the printedmodel into the resin for a new layer of cured resin to be added afterthe irradiation step. The main disadvantage of the top-to-bottom3D-printing technique is the fact that the model being printed has to besubmerged in the resin deeper and deeper after every layer 3D-printing.Hence, this limits the top-to-bottom 3D-printing technique to a heightand/or total size of the model which is limited by the volume of resin.U.S. Pat. No. 5,236,637 to Hull details about a stereo lithographicsystem for automatic generation of three-dimensional objects on alayer-by-layer basis by alternately forming layers of medium overpreviously formed layers of the object. Further, the Hull also describesselectively solidifying successive layers of medium at a surface of abody of the medium whereby the object is formed from a plurality ofsolidified and adhered layers. A limitation to the Hull technique isthat it involves full immersion of the object in the resin which canconstitute some mechanical constraints with respect to the size of thethree-dimensional object to be produced.

In the bottom-to-top 3D-printing technique, the need to use deep wellsof resin for 3D-printing “tall” models is eliminated. The bottom-to-top3D-printing technique requires only relatively shallow well or pool ofresin is used. The main limiting factor is the so-called separation stepthat is needed, since upon the curing of each layer, the printed modelmust be separated carefully from a bottom plate in the fabrication well.Often this requires additional mechanical components and steps due tophysical and chemical interactions between the printed model the bottomplate. In U.S. Pat. No. 7,438,846 to John an elastic gel separatinglayer is arranged between the bottom plate and the model in order toseparate “undestructively” the solidified material from the plate. U.S.Pat. Application No. 2013/0292862 to Joyce describes devices, methods,and computer program products for facilitating the assembly ofthree-dimensional parts in a layer-wise fashion. Joyce describesseparation forces between the assembler device and polymers,photopolymers and metals being minimized at certain interfaces by theutilization of a cure inhibiting layer on a top surface of the imageplate and by sliding the part from contact with a portion of the imageplate having high elevation to above a portion of the image plate withlow elevation. A three-dimensional object may be produced in cascadedlayers from a liquid resin that solidifies upon exposure to light. Atranslation stage may be positioned relative to a vat that is suitablefor solidifying the highest un-solidified layer of the three-dimensionalobject directly beneath any existing, solidified layers of thethree-dimensional object.

U.S. Pat. Application No. 2013/0295212 to Chen discloses a mask imageprojection system that may project a two-dimensional image of thehighest un-solidified layer through a transparent bottom of the vat andinto the liquid resin. Chen also describes allowing the liquid resin tosolidify in the shape of the two-dimensional image and allowing it toadhere to the bottom of a surface beneath the solidified layer.Recently, Carbon3D, Inc. of Redwood City, Calif. (see U.S. Pat. No.9,205,601 to DeSimone and U.S. Pat. No. 9,211,678 to DeSimone)introduced the Continuous Liquid Interphase Printing (CLIP) method,wherein an optically transparent film (such as Teflon AF®) that isoxygen permeable is used. The oxygen acts as a polymerization inhibitorof the resin and thus maintains a dead zone of the polymerizable liquidin contact with the build surface. While such a method would eliminatethe separation (“peeling”) step and the use of a mechanical step toaccomplish this, it complicates the whole method of 3D-printing at boththe software and hardware levels since the control of the amount ofoxygen (the inhibitor) in the described dead zone is accomplished byoxygen sensors and feedback from the software. In addition, the filmwhich is used is made by extrusion methods and thus its width is sizelimited by the process and consequently only small models (width wise)may be printed.

An additional limitation in the currently used building plates in thebottom-to-top DLP 3D-printing technique is the size of the vat. Largesolid supporting plates used in the process are difficult to level dueto the weight of the resin and hence distortion in the printed modeloften results. This is a significant problem when the build plate ismade of a malleable membrane such as Teflon AF (WO Pat. No. 2016/025579to DeSimone) or PDMS based sheets (U.S. Pat. No. 7,438,846 to John).

In some prior art references (see, e.g., US Patent App. 2013/0295212 toChen, US Patent App. 2013/0292862 to Joyce, U.S. Pat. No. 8,905,739 toVermeer, U.S. Pat. No. 9,486,964 to Joyce and U.S. Pat. No. 9,034,237 toSperry), a mechanical step is introduced for the separation process andmay complicate the apparatus, slow the method, and/or potentiallydistort the end product. In addition, this may also have negativeeffects on the resolution and speed of the print.

The various prior art references discussed above disclose differentapproaches that may introduce a mechanical step in the process of threedimensional printing. Introduction of mechanical step complicates thesystem to be used in the three dimensional printing, slows down theprocess, and often distorts the end product. Additionally, solid-liquidinterface used in these three-dimensional printing systems can result inweaknesses in terms of end-product distortion and delays 3D-printingspeeds related to the solidification duration of the liquid resin, inaddition to wearing out with time. Moreover, many of the bottom-to-topDLP printing techniques are limited to the size of the building platedue to the property of the plate material used (malleable and/or ofsmall size).

Accordingly, there is a need for improved methods and systems forprinting three dimensional objects.

SUMMARY

Aspects of the invention pertain to a system for printing of threedimensional objects using a liquid-matrix support. In an embodiment, thesystem comprises a motor, a resin, a stage, oil, and a light projectingsource. The motor and the stage are connected in manner whereby themotor is adapted to move the stage in an upward or a downward direction.The resin is a light polymerizable liquid. A light from the lightprojecting source is projected on the resin to provide a shape to thethree dimensional objects. The stage is adapted to move in the upward orin the downward direction to support the growing layers of the printedthree dimensional objects upon irradiation by light (radiant energy(e.g., UV, Vis, IR, microwaves)) from the light projecting source. Theoil is a non-aqueous hydrophobic and oleo-phobic component and islayered below the resin. The light projecting source is configured toaccomplish the irradiation process.

In an embodiment, the liquid-matrix support in the system is a liquidbilayer made of immiscible oil, a resin, and an additive there between.In another embodiment, the oil in the liquid-matrix support provides aliquid support for the resin. In another embodiment, the resin comprisespolymerizable liquids (such as acrylates, urethanes, epoxies, etc.) andadditives. The resin may be selected from a group of combinations ofmono-acrylate, di-acrylate, tri-acrylate, tetra-acrylates,poly-acrylate, urethanes, poly-urethanes, epoxy and/or their oligomers.The additives in the liquid-matrix support are represented by theformula Rf-X-R. Rf represents per fluorinated alkyl groups such asCF₃(CF₂)n-, CF₃(OCF₂CF₂)_(n)—, CF₃(OCF₂CF₂CF₂)_(n)—,CF₃[CF(CF₃)—CF₂—O]_(n)— where n=1 to 30. X represents any chemicallinkage group from the family of ethers, esters, amides or a single bondbonding together Rf and R. In the case of the ethers and esters, theether or ester will have two to thirty carbons and at least one oxygenin the case of an ether and at least one oxygen and one carbonyl moietyin the case of an ester. In the case of an amide the chemical linkagewill have one to thirty carbons and at least one carbonyl-amino moiety.R represents a non-fluorinated alkyl, alkenyl, alkynyl, or aryl groupswith or without functional groups such as alcohols, amines, ethers orpolyethers, esters, amides, etc. (e.g., R may be substituted with alkylssuch as methyls, ethyls and other alkyls; one or more amino groups;cyano groups; sulfur containing moieties; halogens; oxygen containingmoieties (e.g., hydroxyls); ethers; and esters, with the primaryrequirement being that R is not fluorinated). The arrangement of Rh-X-Rhas fluorinated moieties and non-fluorinated moieties at opposite endsof the molecule. One or more different additives can be used in theresin.

In an embodiment, the oil is selected from aliphatic and polymericperfluorinated compounds represented from CF₃(CF₂)n-, CF₃(OCF₂CF₂)_(n)—,CF₃(OCF₂CF₂CF₂)_(n)—, CF₃[CF(CF₃)—CF₂—O]_(n)— with the value of ‘n’ from10 to 100. In another embodiment, the oil is selected from the group,but not limited to, Krytox oil-103, Krytox oil-104, Krytox oil-105,Krytox oil-106, Krytox oil-107, Krytox oil XHT oils (Dupont®), Demnumoils (Daikin®), Dyneon oils (3M®), fluorinert FC-70 (3M®),(perfluorodecalin, Perfluoroperhydrophenanthrene,Perfluoromethyldecalin, or Perfluoroperhydrobenzyltetralin.

In another embodiment, the liquid-matrix support in the system decreasesthe surface tension of the resin in the printed three dimensionalobjects. In further embodiments, the liquid-matrix support decreasesinteraction of the printed three dimensional objects with the oil whilethe stage moves in the upward direction. In another embodiment, theliquid-matrix support in the system increases the “surface energy” ofthe oil in order to increase the oil's wetting by the resin.

In one embodiment, the resin in the liquid-matrix support is adapted toquickly cure while printing the three dimensional objects. In anotherembodiment, the additives work at the liquid-matrix interface of theresin and the oil to provide a smooth texture of the printed threedimensional objects. In another aspect, the liquid-matrix supportenables printing at speeds up to 20-30 mm/min for the printing of thethree dimensional objects while maintaining high resolution of thefinished product.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein will be better understood from the followingdetailed description with reference to the drawings, in which:

FIG. 1 is a schematic of a system for printing the three dimensionalobjects according to an embodiment herein;

FIG. 2 is a perspective view of the liquid-matrix support in the systemfor printing the three dimensional objects according to an embodimentherein; and

FIG. 3 illustrates a diagrammatic view of the additive orientation atthe liquid-matrix interface of FIG. 2 in the system for printing thethree dimensional objects according to an embodiment herein.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The embodiments herein and the various features and advantageous detailsthereof are explained more fully with reference to the non-limitingembodiments that are illustrated in the accompanying drawings anddetailed in the following embodiments. Description of well-knowncomponents and processing techniques are omitted so as to not obscurethe embodiments herein. The examples used herein are intended merely tofacilitate an understanding of ways in which the embodiments herein maybe practiced and to further enable those skilled in the art to practicethe embodiments herein. Accordingly, the examples should not beconstrued as limiting the scope of the embodiments herein.

As mentioned, there remains a need for a system for printing the threedimensional objects using a method that enhances speed of printing ofthree dimensional objects, large sizes of three dimensional objects, andwith high resolution and smooth finishing texture to the threedimensional objects. The embodiments herein achieve this by providing asystem that comprises a liquid-matrix that works as a non-stickingsupport and ensures high quality texture and high 3D-printing speeds.Referring now to the drawings, and more particularly to FIGS. 1 through3, where similar reference characters denote corresponding featuresconsistently throughout the figures, there are shown preferredembodiments.

FIG. 1 illustrates a perspective view of a system 100 for printing threedimensional objects using a liquid-matrix support according to anembodiment herein. The system 100 includes a motor 102, a resin 104, astage 106, oil 108, and a light projecting source 110. The motor 102 isadapted to move the stage 106 in an upward or in a downward direction.The resin 104 is light polymerizable. The light from the lightprojecting source 110 is projected onto the resin 104 to provide a shapefor the three dimensional objects. In an embodiment, the stage 106 isimmersed in a layer of the resin 104. In another embodiment, the stage106 is adapted to support the growing layers of the three dimensionalobject printed by the system 100. In one embodiment, the oil 108comprises a non-aqueous hydrophobic and oleo-phobic component. Inanother embodiment, the oil 108 is layered below the resin 104 andprovides a liquid support for the resin 104. In another embodiment, theoil 108 does not interfere with the irradiated light. In anotherembodiment, the light projecting source 110 is configured to accomplishirradiation process by projecting the light on the resin 104. In oneembodiment, the light projecting source 110 is, but not limited to, a UVlight emitting diode (LED) or digital light processing equipment. Inanother embodiment, the light projecting source 110 is operated by amercury lamp and results in high output of UV light of appropriatewavelength. In another embodiment, the mercury lamp is configured forinitiation of the polymerization process based on polymerizinginitiators added to the resin 104. In an embodiment, the liquid-matrixsupport in the system 100 is a liquid bi-layer made of immiscible oil108, the resin 104 and an additive there between.

FIG. 2 illustrates a perspective view 200 of the liquid-matrix support202 of FIG. 1 according to an embodiment herein. The resin 104 and theoil 108 are adapted to layer with each other at the liquid-matrixsupport 202. In one embodiment, the resin 104 is formulated to includeadditives for printing three dimensional objects. In one embodiment, theresin 104 includes acrylates that are selected from the group comprisingof mono acrylates, di-acrylates, tri-acrylates, tetra-acrylates,urethanes, epoxy resins, oligomers or a combination of thereof. Inanother embodiment, the additives at the liquid-matrix support 202 areincluded from an amphiphilic family of compounds. In another embodiment,the additives are comprised from the formula—‘Rf-X-R’. ‘Rf’ comprisesper fluorinated alkyl groups selected from alkyl group comprising ofCF₃(CF₂)n-, CF₃(OCF₂CF₂)_(n)—, CF₃(OCF₂CF₂CF₂)_(n)—,CF₃[CF(CF₃)—CF₂—O]_(n)—. The value of ‘n’ in ‘Rf’ is selected from therange of 1-30. ‘X’ comprises a linkage group selected from ethers,amides, esters or a single bond connecting Rf and R. ‘R’ is selectedfrom non-fluorinated alkyl, alkenyl, alkynyl, or aryl groups with orwithout functional groups such as alcohols, amines, ethers orpolyethers, esters, or amides.

In another embodiment, the oil 108 includes, but not limited to, Krytoxoil-103, Krytox oil-104, Krytox oil-105, Krytox oil-106, Krytox oil-107,Krytox oil XHT (Dupont®), Demnum 5-20, Demnum 5-65, Demnum S-200(Daikin®), Dyneon oils (3M®), fluorinert FC-70 (3M®), perfluorodecalin,Perfluoroperhydrophenanthrene, Perfluoromethyldecalin, orPerfluoroperhydrobenzyltetralin.

In another embodiment, the liquid-matrix support 202 is adapted todecrease the surface tension of the resin 104 in the printed threedimensional objects. In another embodiment, the liquid-matrix support202 is adapted to decrease interaction of printed three dimensionalobjects with the oil 108 during the upward movement of the stage 106. Inanother aspect, the resin 104 is adapted for fast curing of the printedthree dimensional objects. In another embodiment, the additives work atthe liquid-matrix support 202 at the interface of the resin 104 and theoil 108 to increase the surface energy of the latter. In anotherembodiment, the additives work at the liquid-matrix support 202 at theinterface of the resin 104 and the oil 108 to increase the wetting ofthe resin 104 on the oil 108 surface. In another embodiment, theadditives work at the liquid-matrix support 202 at the interface of theresin 104 and the oil 108 causes the creation of a smooth texture of theprinted three dimensional objects.

In an embodiment illustrated in FIG. 1, the stage 106 is adapted to movein the upward direction from the liquid-matrix support 202 (shown inFIG. 2) and continues the movement until the resin 104 solidifies toprovide shape to the printed three dimensional objects in a sequentialor non-sequential movement. In another embodiment, the 3D-printingmethod is configured to provide a speed of up-to 30 mm/min for printingthe three dimensional objects. In alternative embodiments, the motor 102may move the stage in downwardly towards the interface between the oil108 and resin 104 (i.e., the liquid-matrix support 202), or bothupwardly and downwardly depending on the application. The volume shownin blank above the resin 104 can accommodate additional resin which canbe added before or during formation of the 3D object.

FIG. 3 illustrates a diagrammatic view 300 of the additive orientationat the liquid-matrix support 202 of FIG. 2 according to an embodimentherein. The additive orientation is adapted in a manner that ‘Rf’ isdownwardly embedded in the oil 108. ‘X’ of the additives is embeddedupwardly in a linkage with ‘R’ towards the resin 104. In an embodiment,the additive orientation, is adapted to decrease the interaction of thethree dimensional printed object with the oil 108 when the stage 106moves up. In an embodiment, the additive orientation decreases thesurface tension of the resin 104 at the liquid-matrix support 202. In anembodiment, the additive orientation increases the surface energy of theoil 108 at the liquid-matrix support 202. The decrease in theinteraction of the three dimensional printed objects with the oil 108,the increase of surface energy at the liquid-matrix interface 202, theincrease in the wettability of the oil 108 by the resin 104, and thedecrease in the surface tension of the resin 104 at the liquid-matrixinterface 202 improve the texture of the printed three dimensionalobjects and allow for high 3D-printing speeds.

In an embodiment, the perfluorinated oil comprise short aliphaticrepeating units and polymeric repeating units selected from the groupcomprising of CF₃(CF₂)n-, CF₃(OCF₂CF₂)_(n)—, CF₃(OCF₂CF₂CF₂)_(n)—,CF₃[CF(CF₃)—CF₂—O]_(n)—, where n=10 to 100. In another embodiment, theoil 108 that is layered below the resin 104 and the liquid-matrixsupport 202 is optically clear. The oil 108 is adapted with a kinematicviscosity of at least 75-95 centistokes at 20° C.-30° C., preferablyhigher than 500 centistokes at 20° C.-30° C. In another embodiment, theboiling point of the oil 108 is at least 150° C.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the embodiments herein that others can, byapplying current knowledge, readily modify and/or adapt for variousapplications such specific embodiments without departing from thegeneric concept, and, therefore, such adaptations and modificationsshould and are intended to be comprehended within the meaning and rangeof equivalents of the disclosed embodiments. It is to be understood thatthe phraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Therefore, while the embodimentsherein have been described in terms of preferred embodiments, thoseskilled in the art will recognize that the embodiments herein can bepracticed with modification within the spirit and scope of the appendedclaims.

1. A system for printing three dimensional objects using a liquid-matrixsupport, wherein the system comprises: a motor; a resin; a stage; oil;and a light projecting source, wherein the motor is an operatinginterface that is adapted to move the stage in an upward or in adownward direction; wherein the resin is a light polymerizable liquid,wherein a light from the light projecting source is projected on theresin so as to provide a shape to three dimensional objects; wherein thestage is adapted to support growing layers of the three dimensionalobjects upon irradiation of light; wherein the oil is a non-aqueoushydrophobic and oleo-phobic component, wherein the oil is layered belowthe resin; and wherein the liquid-matrix support is a liquid bi-layerformed from one or more additives.
 2. The system of claim 1, wherein theliquid-matrix support is created between the resin and the oil.
 3. Thesystem of claim 2, wherein the oil functions as a liquid support for theresin, wherein the resin is selected from the group consisting ofurethanes, epoxy and/or acrylates, and selected from a group ofcombinations of mono-acrylate, di-acrylate, tri-acrylate,tetra-acrylates, poly-acrylate, urethanes, poly-urethanes, epoxy witholigomers and additives, wherein the additives are in the resin and arerepresented by the formulaRf-X-R where Rf is a perfluorinated alkyl group selected from the groupconsisting of CF₃(CF₂)n-, CF₃(OCF₂CF₂)n-, CF₃(OCF₂CF₂CF₂)n-, andCF₂[CF(CF₃)—CF₂—O]n- where n=1 to 30; X is a chemical linkage having oneor more ethers, esters, or amides between Rf and R, or is a single bondconnecting Rf and R; and R is a non-fluorinated alkyl, alkenyl, alkynyl,or aryl group with functional groups selected from the group consistingof such as are alcohols, amines, ethers, esters, and amides; and whereinthe oil is selected from group comprising of aliphatic and polymericperfluorinated compounds represented as of CF₃(CF₂)n-, CF_(OCF₂CF₂)n-,CF₃(OCF₂CF₂CF₂)n-, and CF₂[CF(CF₃)—CF₂—O]n- where n=10 to
 100. 4. Thesystem of claim 1, wherein the oil is selected from a group consistingof perfluorodecalin, perfluoroperhydrophenanthrene,perfluoromethyldecalin, and perfluorperhydrobenzyltetralin.
 5. Thesystem of claim 1, wherein the liquid-matrix support is adapted todecrease the surface tension of the resin in the printed threedimensional objects.
 6. The system of claim 1, wherein the liquid-matrixsupport is adapted to decrease interaction of printed three dimensionalobjects with the oil while the stage moves in the upward direction. 7.The system of claim 1, wherein the liquid-matrix support is adapted toincrease surface energy of the oil in order to increase wetting of theoil by the resin.
 8. The system of claim 2, wherein the additives workat the liquid-matrix support of the resin and the oil to provide asmooth texture to the printed three dimensional objects.
 9. The systemof claim 1, wherein the system is configured to operate at a speed up to20-30 mm/min for printing the three dimensional objects.
 10. A systemfor printing of three dimensional objects using a liquid-matrix support,wherein the system comprises: a motor that is an operating interfacethat is adapted to move a stage in one or more of an upward directionand a downward direction; a resin that is a light polymerizable liquid;one or more additives in the resin; a light projecting source which isconfigured to project light on the resin to provide a shape to threedimensional objects created from polymerized resin; a stage that isadapted to support the growing layers of the three dimensional objects;oil that is a non-aqueous hydrophobic and oleo-phobic component, whereinthe oil is layered with the resin, wherein the oil is a liquid supportfor the resin; wherein the liquid-matrix support is a liquid bi-layerformed from one or more additives; wherein the resin comprises one ormore of acrylates, on urethanes, and epoxies; and wherein the one ormore additives in the resin are represented by the formulaRf-X-R where Rf is a perfluorinated alkyl group selected from the groupconsisting of CF₃(CF₂)n-, CF₃(OCF₂CF₂)n-, CF₃(OCF₂CF₂CF₂)n-, andCF₂[CF(CF₃)—CF₂—O]n- where n=1 to 30; where X is a linkage groupcontaining one or more ethers, esters, or amides linking Rf and R, or isa single bond linking Rf and R; and wherein R is a non-fluorinatedalkyl, alkenyl, alkynyl, or aryl group with functional groups selectedfrom alcohols, amines, ethers, esters, and amides.
 11. The system ofclaim 10, wherein the oil is selected from the group consisting ofperfluorodecalin, perfluoroperhydrophenanthrene, perfluoromethyldecalin,and perfluorperhydrobenzyltetralin.
 12. The system of claim 10, whereinthe liquid-matrix support is adapted to decrease the surface tension ofthe resin in printing the three dimensional objects.
 13. The system ofclaim 10, wherein the liquid-matrix support is adapted to decreaseinteraction of the printed three dimensional objects with the oil whilethe stage moves in the upward direction.
 14. The system of claim 1,wherein the liquid-matrix support is adapted to increase wetting of theoil with the resin.
 15. The system of claim 10, wherein the additiveswork at the liquid-matrix support of the resin and the oil to provide asmooth texture of the printed three dimensional objects. 16-19.(canceled)